Hello @mickylog,
The menu section in the Restro Pro theme takes food items from the items added in the jetpack’s “food menus” post type section.
Please make sure you have installed and activated the jetpack and activated the “custom content type” option from your Admin Dashboard > Jetpack > Settings > Writing > Custom Content Type.
After adding the food items in the dashboard, you can choose the category that you want to display in the front page from the customizer settings.
you can also check the official theme documentation for theme usage from the link here :
http://themepalace.com/theme-instructions/resto-pro/
Hope this Helps,
Best Regards !!